Questions tagged [defragmentation]

The process of arranging blocks on the filesystem to optimize disk read access.

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Effects of copy (cp) vs cut (mv) on file systems

When you have to move a file to a different location in the same file system, you have two options: just cut-paste (or mv), or copy-paste (cp) and then delete the old copy. I'm wondering what are the ...
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Allocate separate regions of disk for static vs changing data, to mitigate fragmentation

I have a home NAS running double-duty to store both never-changing media files, and often-changing backups/misc files. I'm concerned that this will result in a lot of fragmentation. Here's what I ...
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200 views

Identify if IO bottleneck is read or write

I use ddrescue to image failing disk to sparse files - often the files become highly fragmented (>50k fragments). I suspect that sometimes the imaging speed degrades because of the fragmentation. Is ...
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Simultaneous copy from multiple sources without fragmenting destination

I regularly need to copy large datasets from multiple smaller drives to a larger one. Lately I've been using a WD Easystore 12TB External USB 3.0 Hard Drive as my destination. Copying all the files ...
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199 views

How can I disable ext4's automatic defragmentation?

I'm running tests that require some files to be heavily fragmented. I came up with a method to generate fragmented files, but something is working in the background to defragment them. I'm using ...
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152 views

Does BTRFS's compress logic apply when defragmenting?

When mounting a BTRFS filesystem with the compression option, BTRFS will selectively compress files depending on whether they are deemed compressible or not. Does this same logic apply when ...
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Completely defragmenting a FAT32 filesystem [duplicate]

Is there any Linux tool that allows defragmenting a FAT32 filesystem not on a best effort basis, but so that all files are guaranteed to be stored contiguously with no exceptions? Possibly writing the ...
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1k views

Understanding main memory fragmentation and hugepages

I have a machine that is intended for general use and which I also used to run a QEMU virtual machine. Because the virtual machine should be as performant as possible, I want to back the VM memory ...
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2answers
108 views

Switching from Win10 to Linux: AV, defrag, disk cleanup tools, etc [closed]

I installed Linux Mint on my desktop in place of Windows 10. I am used to having virus/malware Scanners, defragmenters, Disk Clean up tools etc. I was wondering if people here would be able to ...
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How to cause the kernel to compact fragmented memory

I am running Fedora 26. This is for a very strange assignment given by my algorithms professor. The assignment says: Memory fragmentation in C: Design, implement, and execute a C-program that ...
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Do rolling releases inevitably cause higher fragmentation over time than point releases? [closed]

Let's compare Debian Stable as a candidate for point releases and Arch Linux as a candidate for rolling releases: Does a rolling release by default cause higher fragmentation on the drive than a ...
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296 views

How to defragment files in size less than 100MB only in ext4 filesystem

I have a very basic idea: I would like to defragment files in size less than 100MB only in ext4 filesystem. Since there is no option for that in the defragmentation tool (e4defrag), any ideas how I ...
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How to filter out only fragmented files from the log?

Supposing I have just finished a defragmentation on ext4 file system on a HDD: sudo e4defrag -v / > ~/defrag-2017-11-05 2>&1 & Which is most probably unnecessary, but I wanted to see, ...
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btrfs — Is it dangerous to defragment subvolume which has readonly snapshots?

If you open the defragment section of btrfs-filesystem(8), you will see the following ominous inscription left by the developers: Warning: Defragmenting with Linux kernel versions < 3.9 or ≥ 3....
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Are there any utilities to know where a file is physically present in the hdd? [duplicate]

I am on Debian testing and using ext4 and ntfs . while ext4 has been brilliant in recovering lost data sometimes it also discards some pieces when electricity goes for a long time or any such similar ...
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299 views

Add & execute package to Defrag a fragmented Ext3 Volume under BusyBox in Synology CS407? How?

Add & execute package to Defrag a fragmented Ext3 Volume under BusyBox in Synology CS407? How? Note: Debunking the myth of Linux Filesystems not getting fragmented. http://www.webupd8.org/2010/...
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8k views

Defragmentation options on Ext4 filesystem

I have the following devices with Linux Mint 18.1 on laptops and GNU/Linux Debian 9 on the server. (All are 64-bit and with Cinnamon desktop.) All drive devices are formatted with ext4 filesystem; ...
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1answer
1k views

How to atomically defragment ext4 directories

Fragmentation seems to create a lot of unnecessary seeks when traversing a directory tree on a HDD: # stat -c %F 00 01 02 directory directory directory # filefrag -v 00 01 02 Filesystem type is: ...
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External Fragmentation in FreeBSD due to unmovable Kernel pages

Is external fragmentation an issue in FreeBSD due to unmovable Kernel pages similar to what Linux (1) (2) faces?
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How to change the extent size in the ext4 file system?

As you can read here , ext4 file system has an extent feature that groups blocks into extents. Each of them can have up to 128MiB contiguous space. In e4defrag , there are lines similar to the ...
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2answers
344 views

Will send & receive also defragment data?

I have heavily fragmented (and 90% full) btrfs partition on my laptop. I'd like to perform defragmentation with the help of identical spare hard drive. I already re-created partition table (GPT) and ...
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1k views

How to defrag XFS file-system if xfs_fsr exits with “no improvement will be made”?

I am trying to defrag a heavily fragmented XFS file-system on a CentOS 6.6 machine: [root@server opt]# xfs_db -c frag -r /dev/md3 actual 598, ideal 215, fragmentation factor 64.05% However, when I ...
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279 views

Meanings of defragmentation and when it is needed

There seem to be two meanings of defragmentation: Defragmentation is a process that reduces the amount of fragmentation. Fragmentation occurs when the file system cannot or will not allocate enough ...
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rsync hangs unless I defrag ext4 filesystem

I have a XBian server (Raspberry Pi version of Debian) running rsync via inetd (not the native dæmon). I am serving a couple of directories on an ext4 filesystem (on a USB disk) as individual modules (...